1. Field of the Invention
The invention relates to a projectile and, in particular, to a device for seeking, tracking, and homing in on a distant target to be destroyed. The target would be a source of electromagnetic (EM) energy, such as infrared radiation (IR) or heat, and would be detected by the device without the use of any electronic components.
2. Description of the Related Art.
Rail guns consisting of a mechanical track and a rapidly varying magnetic or EM field are contemplated as either launch platforms or launch mechanisms for unpowered kinetic energy projectiles which are targeted over hundreds or thousands of kilometers against enemy intercontinental ballistic missiles (ICBMs).
A major constraint in the development of the strategic defense initiative (SDI) for weapon systems is that a projectile must incorporate a homing guidance system capable of first finding and then striking the target. Semiconductor-based infrared sensors and electronics currently under consideration for these defensive weapon systems will be damaged by the highly intense EM field generated by the projection system itself.
The primary conventional solution to this problem is to shield the projectile electronics. However, the magnetic fields are so high that very thick, heavy materials are required to obtain adequate shielding. When these materials are applied and the projectile weight is thus increased, still higher EM fields are required to accelerate the projectile to the necessary launch velocity. Even if the basic problem is solvable by this shielding approach, the resulting defensive weapon is undesirable because of its consequent size and weight, the cost of the required rail gun to launch the projectile, and the fact that a multitude of such weapons must be deployed in continuously orbiting satellites and stations in outer space.
The secondary conventional solution to this problem is to employ nonsemiconductor electronics, which are still capable of being degraded to an unacceptable degree by an EM field. Thus, only fluidic systems appear to offer a viable solution. Examples of some fluidic systems used in projectiles, missiles, and the like, are disclosed in the following U.S. Pat. No.: 3,278,140 of Evans; 3,502,285 of Gambill; 3,645,475 of Stripling; 3,740,003 of Ayre, et al.; 3,920,200 of Evans, et al.; 4,202,517 of Young, et al.; 4,413,795 of Ryan; and 4,532,853 of Stangroom. However, none of these prior art devices embody the tracking of a distant target with fluidic sensors.